Proposals to be submitted to the
Program Advisory Committee
must be received on or before Wednesday, November 1, 2006.
Detailed instructions including important dates may be found on our
website. A list of
including expected intensities is also available.
Some web-based programs may also be beneficial to your planning:
We encourage you to contact us with
suggestions for the beams you require to pursue your physics research.
as to what constitutes a suitable beam for the HRIBF
may be found in our more recent newsletters.
We ask that you be aware that scheduling experiments at our facility is
not straightforward; several experiments must be available before there is
"critical mass" so that it is cost effective to schedule a particular RIB
ion source or endstation configuration.
Additional information reflecting the present status of equipment and
techniques is provided on our
equipment web pages. You are encouraged to
contact the mentor of the equipment should you have any questions.
Information from previous PACs is provided below.
- Ranging out for decay studies
We have begun using our
ranging out technique of neutron-rich
accelerated beams in RIB experiments. Significant reductions in Ga and higher Z
contaminants are observed for neutron-rich Cu isotopes. Two modes of operation
were attempted. By running the ion chamber at full range-out pressure,
the reduction in Z ≥ Z+2 contaminants approaches 100% with a ~50% loss in the desired
isotope. However, the beam spot is enlarged at the point of deposition which
makes absolute measurements involving gamma radiation more challenging and yet,
is beneficial to studies requiring time and position correlations in thick double-sided
silicon strip detectors. By using the ion chamber at lower pressures, one can control
the size of the beam at deposition and adjust the isobar separator to provide similar
results. However, the performance of the isobar separator is dependent on the
beam emittance and mass differences.
We hope to complete a new Low-energy Radioactive Ion Beam
Spectroscopy Station in 2007. This beam line is located
below the tandem (actually attached to the ceiling above
the rotating energy-analyzing magnet) and will take mass-separated
radioactive ion beams directly from the high-resolution
magnet of the RIB injector.
We should be able to use positive and negative ions from
the RIB injector and we hope to have all the usual HRIBF decay
spectroscopy equipment available. Proposals requiring this
beamline will be considered by this PAC but may not be able
to run until late in 2007.
- Rotating target at RMS
A rotating target for decay studies at the RMS has been developed.
Suitable for intense stable beams or even extremely delicate targets for
radioactive beams (e.g. sulfur-compound targets), the stepper-motor
assembly is located inside the vacuum chamber. Initial experiments
with Fe beams on Ni targets have successfully used a factor of 2.5 higher
beam current. A new DC motor coupled with slightly larger targets
(14 mm diameter) is under development.